1. Field of the Invention
The present invention relates to a small-sized electric motor, and more particularly to improvements in a small-sized electric motor comprising: the iron core of a stator, on which a winding is mounted; a rotor rotatably born with a small clearance and in a facing manner within the hole which is formed in the center portion of the stator iron core; and a plurality of end brackets which are equipped with bearings and engaging with said stator iron core for rotatably bearing the rotor.
2. Description of the Prior Art
In a small-sized electric motor according to the prior art, an end bracket is constructed of independent parts, and a rotor is concentrically held on the inner circumference of the iron core of a stator by means of bearings which are mounted in that end brackets. It is, therefore, customary to adopt such a construction that the end brackets and the stator iron core are jointed through the faucet joints which can be interposed inbetween to concentrically position the two and that the two end brackets and the stator iron core are fastened by means of through bolts.
This system according to the prior art, in which the faucet joints are concentrically interposed between the stator iron core and the end brackets thereby to joint the same therethrough, provides easily centering and reliable means but has a defect that the production cost is raised partly because the faucet joints require highly precise machining processes and partly because the front and rear end brackets and the stator iron core have to be machined at four portions.